DE-OS 27 50 035 discloses a hydraulic module having small hydraulic elements interlinkable by their height and surface and performing pressure and/or quantity varying or distributing or controlling functions, and having a base block. The connection pattern of the elements and the base block are configured to be point symmetric, and are in the form of two connecting bores and two fastening bores. In addition, the elements and the base block are mounted in a predetermined pattern and/or sequence and to be rotated around the longitudinal axis through an angle of 180° relative to each other. A space-saving design is thereby obtained for the interlinkable hydraulic elements.
EP 0 854 982 B1 discloses a modular primary valve block of a valve system having pilot-controlled seat and/or piston valves. The primary valve block has both a standardized connection interface and a pilot valve interface for mounting of a pilot valve, and has a pump line, a tank line, a first operating line, a second operating line, a first control line, and a second control line. Four valve seats are mounted in the primary valve block, each for mounting one valve unit. The respective solution has proved to be suitable especially for cartridge technology in which valve units (cartridges) suitable for a particular application are mounted on the primary valve block.
DE 199 21 436 A1 discloses a hydraulic system for supplying a hydraulic consumer in motor vehicles which reduces the cost of designing different alternatives. In this disclosed hydraulic system, a pressure or hydraulic tank is provided in which a hydraulic fluid is stored and may be pressurized. All components of the hydraulic system configured as support housing are mounted so that they form a completely mountable assembly unit. The disclosed solution also has a hydraulic pump which delivers the hydraulic fluid from or to the pressure tank. An electric motor is provided for driving the hydraulic pump, as well as a control device for controlling operation of the electric motor. A pressure accumulator stores pressure in the form of potential energy, and applies this pressure to the hydraulic fluid of the pressure tank and the pump module in the interior of the pressure tank. The other modules are mounted externally on the pressure tank. The disclosed configuration of a hydraulic system provides a modular system by which a plurality of functions may be performed.
These disclosed solutions are not, however, suitable for meeting the increasingly complex system requirements set for hydraulic systems. The control expenditures for such hydraulic control units and associated assembly components has increased. More and more individual solutions are being sought rather than modular concepts, since the disclosed modules or components as supplements to a hydraulic module normally do not sufficiently justify the increased system and control expenditures.